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Archive for October, 2009

Argument From Ignorance

October 30th, 2009 Comments off

Taxonomy – Where am I?

Argument From Ignorance (ad ignorantiam)

classification : informal – fallacies of defective induction

A logical fallacy of irrelevance occurring when one claims that something is true only because it hasn’t been proved false, or vice versa.

Foundations

A claims truth or falsity depends upon supporting or refuting evidence to the claim in favor of an alternative view. Not knowing that a statement is true is taken to be proof that it is false.

Examples

Jim said he is smarter than David but failed to prove it. Therefore his argument ( assertion ) is logically flawed. Claiming something does not make it true.

Failing to prove that Unicorns do not exist, affirms that they do exist

If such actions were not illegal, then they would not be prohibited by the law.

Other Names:

lack-of-knowledge inference

negative evidence

default reasoning

Categories: Logic

Complex Cause

October 28th, 2009 Comments off

Taxonomy – Where am I?

Complex Cause

classification : informal – causal fallacies

The effect is caused by a number of objects or events, of which the cause identified is only a part. A variation of this is the feedback loop where the effect is itself a part of the cause.

Foundations

A complex event is shown as having only one cause.

Examples

People are in fear because of increased crime. (True, but this has lead people to break the law as a consequence of their fear, which increases crime even more.)

We lost the game because Wilson missed the last shot.

What you need to sail around the world is determination.

Other Names

Circular Reasoning

Categories: Logic

Joint Effect

October 24th, 2009 Comments off

Taxonomy – Where am I?

Joint Effect

classification : informal – fallacies Of ambiguity

Joint effect is a logical fallacy of causation in which two phenomena that have a common cause are thought to be cause and effect themselves.

Foundations

This is a special case of correlation implies causation. In statistics, the common cause is called a confounding factor and this fallacy is called a spurious relationship.

Examples

We are experiencing high unemployment which is being caused by a low consumer demand. (In fact, both may be caused by high interest rates.)

You have a fever and this is causing you to break out in spots. (In fact, both symptoms are caused by the measles.)

Other Names

A special case of post hoc ergo prompter hoc.
fallacy of causation
fallacy of the single cause
causal oversimplification
Spurious relationship
false dilemma

Categories: Uncategorized

Loki’s Wager

October 23rd, 2009 Comments off

Taxonomy – Where am I?

Loki’s Wager

classification : informal – fallacies Of ambiguity

It is the unreasonable insistence that a concept cannot be defined, and therefore cannot be discussed.

Foundations

The fallacy’s focus on over specification makes it in some ways the opposite of hasty generalization and could be considered an extreme form of equivocation. Used, intentionally or not, as a stalling or diversionary tactic which ensures that the real issue need never be debated because there can be no consensus on the terms of debate.

Examples

Loki is a trickster god in Norse mythology, who, legend has it, once made a bet with some dwarves. It was agreed that the prize, should Loki lose the wager, would be his head. Loki lost the bet, and in due time the dwarfs came to collect the head which had become rightfully theirs. Loki had no problem with giving up his head, but he insisted they had absolutely no right to take any part of his neck. Everyone concerned discussed the matter and concluded that Loki was correct. Certain parts were obviously head, and certain parts were obviously neck, but neither side could agree exactly where the one ended and the other began. As a result, Loki keeps his head indefinitely. ( The same principle as the “pound of flesh but not a drop of blood” in The Merchant of Venice. )

Other Names

Equivocation
False attribution
Quoting out of context
No true Scotsman
Reification

Categories: Logic

Wishful Thinking

October 8th, 2009 Comments off

Taxonomy – Where am I?

Wishful Thinking

classification : informal – Red Herring – Appeal to Emotion

Believing something because of a desire – wish – that it be true. As a logical fallacy, Wishful Thinking is an argument whose premise expresses a desire for the conclusion to be true.

Foundations

A reasoner who suggests that a claim is true, or false, merely because he or she strongly hopes it is, is committing the fallacy of wishful thinking. Wishing something is true is not a relevant reason for claiming that it is actually true.

Examples

There’s got to be an error here in the history book. It says Thomas Jefferson had slaves. He was our best president, and a good president would never do such a thing. That would be awful.

Other Names

Appeal to Consequences
Emotional Appeal
Negative proof
Argument from ignorance
Cognitive Dissonance
Defense Mechanisms
Pygmalion Effect

Categories: Logic

Appeal To Spite

October 8th, 2009 Comments off

Taxonomy – Where am I?

Appeal To Spite (argumentum ad odium)

classification : informal – red herring – emotional appeal

The Appeal to Spite Fallacy is a fallacy in which spite is substituted for evidence when an “argument” is made against a claim. They attempt to elicit an emotional response that will serve as the basis of any decision made, instead of presenting an argument and relying on its soundness.

Foundations

This sort of reasoning is fallacious because a feeling of spite does not count as evidence for, or against, a claim. Appeal to spite should not be confused with fallacious ad hominem arguments which attack the people or groups associated with a particular view or belief in an attempt to discredit it.

Examples

Bill claims that the earth revolves around the sun. But remember that dirty trick he pulled on you last week. Now, doesn’t my claim that the sun revolves around the earth make sense to you?

“If you vote for this tax cut, it will mean that the fat cats will get even more money to spend on their expensive luxury yachts, while you and I keep struggling to pay the bills.”

Other Names

Argumentum ad odium

Appeal to emotion

Cutting off the nose to spite the face

Categories: Logic

Appeal To Flattery

October 8th, 2009 Comments off

Taxonomy – Where am I?

Appeal To Flattery

classification : informal – red herring – emotional appeal

Flattery and excessive compliments are presented in the place of evidence for accepting a claim generally for the purpose of ingratiating oneself with the subject. It is fallacious because flattery is not, in fact, evidence for a claim.

Foundations

Flattery is often used to hide the true intent of an idea or proposal. Praise offers a momentary personal distraction that can often weaken judgment.

Examples

“That was a singularly brilliant idea. I have never seen such a clear and eloquent defense of Plato’s position. If you do not mind, I’ll base my paper on it. Provided that you allow me a little extra time past the deadline to work on it.”

Surely a man as smart as you can see this is a brilliant proposal.

Other Names

Apple Polishing
Appeal to emotion
Superficial charm
Flattery
Appeal to consequences

Categories: Logic

Appeal To Motive

October 8th, 2009 Comments off

Taxonomy – Where am I?

Appeal To Motive

classification : informal – red herring – genetic fallacy – ad hominem

A pattern of argument which consists in challenging a thesis by calling into question the motives of its proposer. It can be considered as a special case of the ad hominem circumstantial argument.

Foundations

Appeals to Motive in Place of Support. A common feature of appeals to motive is that only the possibility of a motive (however small) is shown, without showing the motive actually existed or, if the motive did exist, that the motive played a role in forming the argument and its conclusion. Indeed, it is often assumed that the mere possibility of motive is evidence enough.

Examples

The referee comes from the same place as (a sports team), so his refereeing was obviously biased towards them.

Other Names

ad hominem circumstantial

Bulverism

fallacies of relevance

Included Fallacies

Appeal to Force
Appeal to Pity
Appeal to Consequences
Prejudicial Language
Appeal to Popularity

Categories: Logic

Appeal To Fear

October 8th, 2009 Comments off

Taxonomy – Where am I?

Appeal To Fear ( argumentum ad metum or argumentum in terrorem )

classification : informal – Appeal to Emotion

Occurs when a person attempts to create support for his or her idea by using deception and propaganda in attempts to increase fear and prejudice toward a competitor but does not constitute evidence for the claim.

Foundations

A fallacy that appeal to emotion is a type of argument which attempts to arouse the emotions of its audience in order to gain acceptance of its conclusion.

Appeals to fear are common in advertising, conspiracy theories, politics, propaganda, and promotion of alternative medicine. It is a useful tool for anyone who wishes to influence the behaviour of others.

It is important to distinguish between a rational reason to believe or evidence (evidence that objectively and logically supports the claim) and a prudential reason to believe or motivation. Fear appeals seldom gain more than compliance. Emotional and intellectual agreement will lag far behind and may never be gained.

Examples

I know where you live, and I have friends who like a good fire.

If you do not convict this criminal, one of you may be her next victim.

Other Names

Appeal to emotion
Appeal to Consequence
Ad Baculum
Ad Metum
Appeal to Force
In Terrorem
Scare Tactics

Categories: Logic

Appeal To Novelty

October 8th, 2009 Comments off

Appeal To Novelty ( argumentum ad novitatem )

classification : informal – appeal to emotion

A fallacy in which someone prematurely claims that an idea or proposal is correct or superior, exclusively because it is new and modern.

Foundations

In a controversy between status quo and new inventions, an appeal to novelty argument isn’t in itself a valid argument. The fallacy may take two forms: overestimating the new and modern, prematurely and without investigation assuming it to be best-case, or underestimating status quo, prematurely and without investigation assuming it to be worst-case.

Examples

If you want to lose weight, your best bet is to follow the latest diet.

Upgrading all your software to the most recent versions will make your system more reliable.

Other Names

Ad Novitam
Bandwagon fallacy
argumentum ad antiquitatem

Note: The opposite of an appeal to novelty is an appeal to tradition.

Categories: Logic